Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
Nothing in the history of modern astronomy has excited as much speculation as the object, or event, known as a black hole. Black holes have provided endless imaginative fodder for science fiction writers and endless theoretical fodder for astrophysicists. They are one of the more exotic manifestations of the theory of general relativity, and their fascination lies in the way their tremendous gravity affects nearby space and time.
A black hole is very simple in structure: it has s surface – the event horizon – and a centre – the singularity. Everything else is gravity. The standard model for the formation of a black hole involves the collapse of a large star. The imaginary spherical surface surrounding the collapsed star is the event horizon – an artificial boundary in space that marks a point of no return. Outside the event horizon, gravity is strong but finite, and it is possible for objects to break free of its pull. However, once within the event horizon, an object would need to travel faster than light to escape.
For extremely massive stars, the exclusion principle – the resistance between the molecular particles within the star as they are compressed – will not be strong enough to offset the gravity generated by the star’s own mass. The star’s increasing density will overwhelm the exclusion principle. What follows is runaway gravitational collapse. With no internal force to stop it, the star will simply continue to collapse it on itself. Once a collapsing star has contracted through its event horizon, nothing can stop it from collapsing further until its entire mass is crushed down to a single point – a point of infinite density and zero volume – the singularity.
The star now disappears from the perceivable universe, like a cartoon character that jumps into a hole and pulls the hole in after him. What this process leaves behind is a different kind of hole – a profound disturbance in space –time, a region where gravity is so intense that nothing can escape from it. Any objects falling within the boundary of a black hole has no choice but to move inward toward the singularity and disappear from our universe forever. Moreover, a black hole can never be plugged up or filled in with matter; the more matter that is poured into a black hole, the bigger it gets.
What would happen to objects, such as astronauts, as they vanished into a black hole? Physicists have been amusing themselves with this question for years, and most believe that the intense gravitational forces would rip apart the astronauts long before they were crushed singularity. Theoretically, any astronauts who managed to survive the passage would encounter some very strange things. For instance, they would experience acute time distortion, which would enable them to know, in a few brief seconds, the entire future of the universe.
Inside a black hole, space and time are so warped that the distance from the event horizon to the singularity is not a distance in space in the normal sense that we can measure in kilometers. Instead, it becomes a distance in time. The time it takes to reach the singularity from the event horizon – as measured by someone falling in – is proportional to the mass of the black hole.
The only way that astronauts would know whether they had crossed the event horizon would be if they tried to halt their fall and climb out again by firing their engines enough to push themselves back from the center of the hole. However, because of the time warp, if the astronauts tried to do this, they would reach the singularity faster once they had left their engines off. Moreover, since they could get no farther once they had reached the singularity, this point would mark the end of time itself.
A black hole consists of all the following EXCEPT
A.the event horizon                 
B.a strong gravitation force
C.the collapse of a large star
D.the singularity

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
Nothing in the history of modern astronomy has excited as much speculation as the object, or event, known as a black hole. Black holes have provided endless imaginative fodder for science fiction writers and endless theoretical fodder for astrophysicists. They are one of the more exotic manifestations of the theory of general relativity, and their fascination lies in the way their tremendous gravity affects nearby space and time.
A black hole is very simple in structure: it has s surface – the event horizon – and a centre – the singularity. Everything else is gravity. The standard model for the formation of a black hole involves the collapse of a large star. The imaginary spherical surface surrounding the collapsed star is the event horizon – an artificial boundary in space that marks a point of no return. Outside the event horizon, gravity is strong but finite, and it is possible for objects to break free of its pull. However, once within the event horizon, an object would need to travel faster than light to escape.
For extremely massive stars, the exclusion principle – the resistance between the molecular particles within the star as they are compressed – will not be strong enough to offset the gravity generated by the star’s own mass. The star’s increasing density will overwhelm the exclusion principle. What follows is runaway gravitational collapse. With no internal force to stop it, the star will simply continue to collapse it on itself. Once a collapsing star has contracted through its event horizon, nothing can stop it from collapsing further until its entire mass is crushed down to a single point – a point of infinite density and zero volume – the singularity.
The star now disappears from the perceivable universe, like a cartoon character that jumps into a hole and pulls the hole in after him. What this process leaves behind is a different kind of hole – a profound disturbance in space –time, a region where gravity is so intense that nothing can escape from it. Any objects falling within the boundary of a black hole has no choice but to move inward toward the singularity and disappear from our universe forever. Moreover, a black hole can never be plugged up or filled in with matter; the more matter that is poured into a black hole, the bigger it gets.
What would happen to objects, such as astronauts, as they vanished into a black hole? Physicists have been amusing themselves with this question for years, and most believe that the intense gravitational forces would rip apart the astronauts long before they were crushed singularity. Theoretically, any astronauts who managed to survive the passage would encounter some very strange things. For instance, they would experience acute time distortion, which would enable them to know, in a few brief seconds, the entire future of the universe.
Inside a black hole, space and time are so warped that the distance from the event horizon to the singularity is not a distance in space in the normal sense that we can measure in kilometers. Instead, it becomes a distance in time. The time it takes to reach the singularity from the event horizon – as measured by someone falling in – is proportional to the mass of the black hole.
The only way that astronauts would know whether they had crossed the event horizon would be if they tried to halt their fall and climb out again by firing their engines enough to push themselves back from the center of the hole. However, because of the time warp, if the astronauts tried to do this, they would reach the singularity faster once they had left their engines off. Moreover, since they could get no farther once they had reached the singularity, this point would mark the end of time itself.
the phrase this point in paragraph 7 in refers to
A.the event horizon     
B.firing their engines   
C.the time warp            
D.the singularity

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
Nothing in the history of modern astronomy has excited as much speculation as the object, or event, known as a black hole. Black holes have provided endless imaginative fodder for science fiction writers and endless theoretical fodder for astrophysicists. They are one of the more exotic manifestations of the theory of general relativity, and their fascination lies in the way their tremendous gravity affects nearby space and time.
A black hole is very simple in structure: it has s surface – the event horizon – and a centre – the singularity. Everything else is gravity. The standard model for the formation of a black hole involves the collapse of a large star. The imaginary spherical surface surrounding the collapsed star is the event horizon – an artificial boundary in space that marks a point of no return. Outside the event horizon, gravity is strong but finite, and it is possible for objects to break free of its pull. However, once within the event horizon, an object would need to travel faster than light to escape.
For extremely massive stars, the exclusion principle – the resistance between the molecular particles within the star as they are compressed – will not be strong enough to offset the gravity generated by the star’s own mass. The star’s increasing density will overwhelm the exclusion principle. What follows is runaway gravitational collapse. With no internal force to stop it, the star will simply continue to collapse it on itself. Once a collapsing star has contracted through its event horizon, nothing can stop it from collapsing further until its entire mass is crushed down to a single point – a point of infinite density and zero volume – the singularity.
The star now disappears from the perceivable universe, like a cartoon character that jumps into a hole and pulls the hole in after him. What this process leaves behind is a different kind of hole – a profound disturbance in space –time, a region where gravity is so intense that nothing can escape from it. Any objects falling within the boundary of a black hole has no choice but to move inward toward the singularity and disappear from our universe forever. Moreover, a black hole can never be plugged up or filled in with matter; the more matter that is poured into a black hole, the bigger it gets.
What would happen to objects, such as astronauts, as they vanished into a black hole? Physicists have been amusing themselves with this question for years, and most believe that the intense gravitational forces would rip apart the astronauts long before they were crushed singularity. Theoretically, any astronauts who managed to survive the passage would encounter some very strange things. For instance, they would experience acute time distortion, which would enable them to know, in a few brief seconds, the entire future of the universe.
Inside a black hole, space and time are so warped that the distance from the event horizon to the singularity is not a distance in space in the normal sense that we can measure in kilometers. Instead, it becomes a distance in time. The time it takes to reach the singularity from the event horizon – as measured by someone falling in – is proportional to the mass of the black hole.
The only way that astronauts would know whether they had crossed the event horizon would be if they tried to halt their fall and climb out again by firing their engines enough to push themselves back from the center of the hole. However, because of the time warp, if the astronauts tried to do this, they would reach the singularity faster once they had left their engines off. Moreover, since they could get no farther once they had reached the singularity, this point would mark the end of time itself.
What can be inferred  from paragraph 6 about the distance between the event horizon and the singularity?
A.The distance increases and decreases continuously
B.The distance is more than several trillion kilometers
C.The distance cannot be travelled in less than a year
D.The distance is related to size of the black hole

Read the following passage, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
Nothing in the history of modern astronomy has excited as much speculation as the object, or event, known as a black hole. Black holes have provided endless imaginative fodder for science fiction writers and endless theoretical fodder for astrophysicists. They are one of the more exotic manifestations of the theory of general relativity, and their fascination lies in the way their tremendous gravity affects nearby space and time.
A black hole is very simple in structure: it has s surface – the event horizon – and a centre – the singularity. Everything else is gravity. The standard model for the formation of a black hole involves the collapse of a large star. The imaginary spherical surface surrounding the collapsed star is the event horizon – an artificial boundary in space that marks a point of no return. Outside the event horizon, gravity is strong but finite, and it is possible for objects to break free of its pull. However, once within the event horizon, an object would need to travel faster than light to escape.
For extremely massive stars, the exclusion principle – the resistance between the molecular particles within the star as they are compressed – will not be strong enough to offset the gravity generated by the star’s own mass. The star’s increasing density will overwhelm the exclusion principle. What follows is runaway gravitational collapse. With no internal force to stop it, the star will simply continue to collapse it on itself. Once a collapsing star has contracted through its event horizon, nothing can stop it from collapsing further until its entire mass is crushed down to a single point – a point of infinite density and zero volume – the singularity.
The star now disappears from the perceivable universe, like a cartoon character that jumps into a hole and pulls the hole in after him. What this process leaves behind is a different kind of hole – a profound disturbance in space –time, a region where gravity is so intense that nothing can escape from it. Any objects falling within the boundary of a black hole has no choice but to move inward toward the singularity and disappear from our universe forever. Moreover, a black hole can never be plugged up or filled in with matter; the more matter that is poured into a black hole, the bigger it gets.
What would happen to objects, such as astronauts, as they vanished into a black hole? Physicists have been amusing themselves with this question for years, and most believe that the intense gravitational forces would rip apart the astronauts long before they were crushed singularity. Theoretically, any astronauts who managed to survive the passage would encounter some very strange things. For instance, they would experience acute time distortion, which would enable them to know, in a few brief seconds, the entire future of the universe.
Inside a black hole, space and time are so warped that the distance from the event horizon to the singularity is not a distance in space in the normal sense that we can measure in kilometers. Instead, it becomes a distance in time. The time it takes to reach the singularity from the event horizon – as measured by someone falling in – is proportional to the mass of the black hole.
The only way that astronauts would know whether they had crossed the event horizon would be if they tried to halt their fall and climb out again by firing their engines enough to push themselves back from the center of the hole. However, because of the time warp, if the astronauts tried to do this, they would reach the singularity faster once they had left their engines off. Moreover, since they could get no farther once they had reached the singularity, this point would mark the end of time itself.
Astronauts who fell into a black hole would probably experience all of the following EXCEPT?
A.Distortion of space and time          
B.Travelling faster than light
C.Knowing of the universe
D.Strong gravitational forces

Read the following passage, and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer for each of the blanks.
Last summer, air pollution in Paris reached dangerous levels on six separate occasions. As a result, the government have recently decided that public transport in French cities will be (6) ______ on days when pollution becomes a (7) ______ to people’s health, in a(n) (8) ______ to encourage people to leave their cars at home.
The major of Paris said that he had several other ideas to reduce the pollution problem, such as free parking on the (9) ______ of the city on hot, still days when exhaust fumes tend to accumulate. He has also announced a $6 million plan for 56 km of bicycle tracks, new pedestrianised zones and a new tram line for southern Paris. His most popular measure (10) ______ becoming mayor last May has been to (11) ______ traffic from several streets on Sundays.
Every summer, air quality is at its (12) ______ in Paris during holiday weekends, especially one weekend in July when the (13) ______ of the population leave by car for their summer holidays. Conditions then improve for the summer, but deteriorate again when most residents return at the end of August.
The free transport (14) ______ is part of the respond to a new environmental regulation which says that local authorities must guarantee safe air. If it is (15) ______ seriously, local can look forward to a cleaner Paris in the future.

A.outskirts       
B.areas    
C.suburbs     
D.provinces

Read the following passage, and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer for each of the blanks.
Last summer, air pollution in Paris reached dangerous levels on six separate occasions. As a result, the government have recently decided that public transport in French cities will be (6) ______ on days when pollution becomes a (7) ______ to people’s health, in a(n) (8) ______ to encourage people to leave their cars at home.
The major of Paris said that he had several other ideas to reduce the pollution problem, such as free parking on the (9) ______ of the city on hot, still days when exhaust fumes tend to accumulate. He has also announced a $6 million plan for 56 km of bicycle tracks, new pedestrianised zones and a new tram line for southern Paris. His most popular measure (10) ______ becoming mayor last May has been to (11) ______ traffic from several streets on Sundays.
Every summer, air quality is at its (12) ______ in Paris during holiday weekends, especially one weekend in July when the (13) ______ of the population leave by car for their summer holidays. Conditions then improve for the summer, but deteriorate again when most residents return at the end of August.
The free transport (14) ______ is part of the respond to a new environmental regulation which says that local authorities must guarantee safe air. If it is (15) ______ seriously, local can look forward to a cleaner Paris in the future.

A.try    
B.pursuit     
C.trail     
D.effort

Read the following passage, and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer for each of the blanks.
Last summer, air pollution in Paris reached dangerous levels on six separate occasions. As a result, the government have recently decided that public transport in French cities will be (6) ______ on days when pollution becomes a (7) ______ to people’s health, in a(n) (8) ______ to encourage people to leave their cars at home.
The major of Paris said that he had several other ideas to reduce the pollution problem, such as free parking on the (9) ______ of the city on hot, still days when exhaust fumes tend to accumulate. He has also announced a $6 million plan for 56 km of bicycle tracks, new pedestrianised zones and a new tram line for southern Paris. His most popular measure (10) ______ becoming mayor last May has been to (11) ______ traffic from several streets on Sundays.
Every summer, air quality is at its (12) ______ in Paris during holiday weekends, especially one weekend in July when the (13) ______ of the population leave by car for their summer holidays. Conditions then improve for the summer, but deteriorate again when most residents return at the end of August.
The free transport (14) ______ is part of the respond to a new environmental regulation which says that local authorities must guarantee safe air. If it is (15) ______ seriously, local can look forward to a cleaner Paris in the future.

A.risk     
B.terror    
C.threat    
D.damage

Read the following passage, and mark the letter (A, B, C or D) on your answer sheet to indicate the correct answer for each of the blanks.
Last summer, air pollution in Paris reached dangerous levels on six separate occasions. As a result, the government have recently decided that public transport in French cities will be (6) ______ on days when pollution becomes a (7) ______ to people’s health, in a(n) (8) ______ to encourage people to leave their cars at home.
The major of Paris said that he had several other ideas to reduce the pollution problem, such as free parking on the (9) ______ of the city on hot, still days when exhaust fumes tend to accumulate. He has also announced a $6 million plan for 56 km of bicycle tracks, new pedestrianised zones and a new tram line for southern Paris. His most popular measure (10) ______ becoming mayor last May has been to (11) ______ traffic from several streets on Sundays.
Every summer, air quality is at its (12) ______ in Paris during holiday weekends, especially one weekend in July when the (13) ______ of the population leave by car for their summer holidays. Conditions then improve for the summer, but deteriorate again when most residents return at the end of August.
The free transport (14) ______ is part of the respond to a new environmental regulation which says that local authorities must guarantee safe air. If it is (15) ______ seriously, local can look forward to a cleaner Paris in the future.

A.open      
B.loose    
C.off    
D.free

Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the rest in the position of the main stress in each of the following questions.

A.material
B.courtesy
C.receptive
D.majority

Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the rest in the position of the main stress in each of the following questions.

A.millennium
B.lecture
C.different
D.grocery